1. Technical Field
The present invention relates to a recording apparatus that performs recording on a medium.
2. Related Art
An ink jet printer as one example of a recording apparatus will be described hereinbelow by way of example. The ink jet printer includes a recording head mounted on a carriage to eject ink on a recording sheet or paper.
The carriage is configured such that the carriage is guided by a guide member extending in the scanning direction of the recording head (hereinafter referred to as “main scanning direction”), and is fixed to a part of, for example, an endless belt, whereby the traction of the endless belt causes the carriage to reciprocate in the main scanning direction.
Because the position of the carriage at which the endless belt is fixed cannot normally coincide with the position of the center of gravity of the carriage, the phenomenon that the carriage tends to rotate (called “swinging phenomenon”) may occur when the carriage is in traction by the endless belt. This phenomenon lowers the ink landing precision. There are several swinging directions including swinging on an x-z plane and swinging on an x-y plane where y is the sheet transporting direction on the recording surface of a recording sheet, x is a direction (sheet's widthwise direction) orthogonal to the y direction, and z is a direction orthogonal to the recording surface.
JP-A-2006-96028 describes a recording apparatus configured to include an urging section which exerts urging force between a guide member (guide shaft) and a carriage, whereby rotational moment in a given direction is applied to the carriage beforehand so that the rotational moment in the given direction is always produced regardless of the moving direction of the carriage, thereby preventing swinging of the carriage.
JP-A-2004-17314 discloses an image forming apparatus configured in such a way that to suppress rattling between first and second guide members, provided along the moving direction of the carriage, and the carriage, an urging section presses the portions of the carriage which slide in contact with the guide members against the guide members.
Some ink jet printers are configured to be able to adjust the gap between the recording head and a sheet of paper (hereinafter referred to as “PG”), so that adjusting the PG can provide adequate recording results regardless of the thickness of the sheet.
Various mechanisms for adjusting the PG have been proposed. One of the adjusting mechanisms is configured to adjust the PG by changing the height position of the guide member that guides the carriage in the main scanning direction.
Let us consider a case where the PG adjusting mechanism is configured to adjust the PG by changing the relative position on the carriage between a slide member which slides in contact with the guide member, provided fixedly, and the carriage body. More specifically, the PG adjusting mechanism is configured in such a way that a gap adjusting cam to change the PG is provided between the slide member and the carriage body, and is displaced to adjust the position (height) of the carriage body relative to the slide member.
According to this configuration, part of the carriage is mounted on the gap adjusting cam, which is mounted on the slide member mounted on the guide member. However, only the dead weight of the carriage is applied between the carriage and the gap adjusting cam and between the gap adjusting cam and the slide member, so that the carriage may be lifted up from the gap adjusting cam or the gap adjusting cam may be lifted up from the slide member when the carriage is driven, causing swinging of the carriage. The aforementioned recording apparatuses according to the related art do not have such a gap adjusting structure, and are not naturally designed to cope with the aforementioned technical problem.